Farmers anxiously waiting for fresh water
Early in the morning, the Viem Trung field, Dien Ban Dong ward, Da Nang city was already scorching hot. On the rice fields that were in the tillering period, many patches of rice were pale yellow, the surface of the fields was cracked due to lack of water. Mr. Ho Van Dang, 67 years old, plucked rice bushes to see the roots and shook his head: "As soon as the rice took root, the saltwater level rose again, I don't know if this crop will hold on.
Nearly 2,000 hectares of rice in Dien Ban Dong and neighboring areas such as An Thang, Hoi An, Hoi An Dong, Hoi An Tay, Ngu Hanh Son... are dependent on the Vinh Dien river water source, in which Tu Cau pumping station plays an important water supply role.
However, when saltwater intrudes deeply, the station must pump alternately, at times stopping operation to avoid bringing saltwater into the fields.
An station official said that after the Lunar New Year, the salinity on the river increased; when it reached 1.5-2‰, the water was no longer suitable for rice irrigation.
Not only agricultural production is threatened, the domestic water source in the downstream area is also facing risks. The Vinh Dien River currently supplies water to the Hoi An Water Plant and some people's pumping stations along the river.
When saltwater intrudes deeply, the problem is no longer only of the fields but directly affects the meals, living and lives of tens of thousands of people.
In 2026, the salinity situation on the Vinh Dien River is assessed to be more serious than many years ago. At the raw water intake gate into the Cau Do Water Plant, the salinity at times reached 12.3‰, the highest level in about 10 years, a chain reaction to the water security of the area.
Permanent dam opens proactive direction to prevent saltwater intrusion
Under pressure to rescue nearly 2,000 hectares of summer-autumn rice crop, Da Nang City urgently rebuilt the seasonal dam to prevent saltwater intrusion on the Vinh Dien River.
According to Mr. Truong Xuan Ty - Deputy Director of the Department of Agriculture and Environment of Da Nang City, this is an urgent solution to maintain fresh water and ensure irrigation water during peak drought.
However, the leaders of the agricultural sector themselves also recognize that temporary dams are only temporary solutions. Each year, the locality has to spend about 3-4 billion VND to build dams to prevent saltwater intrusion. When the rainy and flood season comes, the project must be dismantled to restore the natural flow, ensuring flood drainage for the downstream area. For more than 10 years, this dam-break cycle has cost over 30 billion VND of the budget.
Former Chairman of Dien Ban Town People's Committee (old) - Mr. Tran Uc once frankly stated that it is not possible to build temporary dams every year, which is both costly, passive, and unsustainable. According to him, a permanent project, if carefully calculated, can fundamentally solve the problem of fresh water shortage for the downstream area.
To date, the permanent saltwater dam project on the Vinh Dien River has been included in the irrigation development plan, included in the medium-term investment portfolio for the 2026-2030 period.
According to Mr. Truong Xuan Ty, the difference between permanent dams and temporary dams is their flexible operation. Temporary dams when built across rivers almost have no flow regulation mechanism, easily creating pressure on downstream areas when floods come. Meanwhile, if building permanent dams, the works must be designed with regulating valve gates, ensuring flow, having plans for ships to circulate and only operating to prevent salinity when necessary.
The latest signal is that at the actual inspection of the seasonal dam to prevent saltwater intrusion and retain freshwater on the Vinh Dien River, Mr. Tran Nam Hung - Member of the Standing Committee of the City Party Committee, Vice Chairman of Da Nang City People's Committee said - the city will invest in building a permanent saltwater dam on the Vinh Dien River, Dien Ban Dong ward area, with a total estimated cost of over 100 billion VND. The city has assigned specialized sectors to develop a project to submit to competent authorities for approval.
The temporary dam can save a crop in an emergency situation, but nearly 2,000 hectares of production and domestic water for tens of thousands of people cannot forever depend on the construction built and then demolished.
Mr. Tran Nam Hung - Vice Chairman of Da Nang City People's Committee said that in the context of climate change, drought and saline intrusion becoming increasingly extreme, the problem on the Vinh Dien River is no longer a seasonal issue, but a test of long-term adaptive infrastructure investment capacity.
